When drawing on a computer (making image data), user draws with one hand by way of a pen table and a mouse, etc. As desiring to zoom in or out an image or a part of the image (referred as “object” hereafter), to move and rotate the object, and to change drawing tool, the user can only click icon(s) displayed in drawing software or type keyboard without using an indicator device, thus causing inconvenient operation with hand(s).
It is efficient to draw with one hand by using the indicator device and to edit illustration with the other hand by ways of other devices. Typically, the one hand is user's right hand and the other hand is user's left hand, the device operated by the other hand is called as a left-hand auxiliary input device (or simply called as a left hand device). For example, JP 2001-265532 disclosed a method of executing rolling operation by using a combination of two devices with the two hands. When drawing by using the indicator device and operating assistance device simultaneously, an input assistance device is operated with a left hand.
As desiring to rotate the object, it is essential to rotate the object at each 45 degrees by using the keyboard (such as determining a rotating angle according to a pressing time), but such an operation is not executed easily. So, a rotating body and a rotary encoder are provided in the input assistance device, wherein the rotary encoder is configured to adjust the rotating angle. Accordingly, it is efficient to draw by way of the rotary encoder.
The input assistance device has some functions, such as zooming in or out of the object, a size change of a brush, and a color density change of the brush, but these functions cannot be selected based on types of signals.
To change multiple drawing functions, a number of rotary encoders corresponding to the multiple drawing functions is required. Alternatively, a sole rotary encoder matches with multiple selective buttons so as to realize multiple drawing functions. However, the user has to remove his/her one hand from the rotary encoder when changing the multiple drawing functions, thus causing troublesome operation.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.